Oil burning furnace



Feb. s, 1938.

Jv. w. 'NELSON 2,107,871

vOIL BURNING FURNACE Original Filed'May 29, 1935 Patented Feb. 8, 1938 kPATENT OFFICE OIL BURNING FURNACE John W. Nelson, Chicago, Ill., assignor to Chicago Flexible Shaft Company, Chicago, Ill., a. corporation of Illinois Original application May 29, 1933, Serial No. 673,-

497. Divided and this application October 1,

`1934, Serial No. 746,403

4 claims. (el. 15s- 5) AThis application is a division of my co-pending application Serial No. 673,497, led May 29,` 1933.

The purpose of this invention is to provide an improved oil-burning furnace particularly adapted for use with a heat-treating apparatus for annealing, case-hardening and like processes. Anobject of the invention is to utilize waste heat from the heat-treatment chamber for gasifying fuel oil'in a retort structure preparatory to feeding it to the burner means which serves the heattreatment chamber. The invention consists in certain features and elements of construction in combination, as herein shown and described and as indicated by the claims.

l In the drawing: f l Figure 1 is a vertical section of an apparatus embodying this invention in one of its forms.

Figure 2 is a similar view of a-slightly modified Figure 3 isa transverse sectiontakensubstantially as indicated at line v3 3 on Figure 2.

V lFigure 4 is a getailsection taken as indicated at line 4--4 on Figure 3.

,-.uReferring to the drawing in detail:

{InI theform shown in Figure 1, A is a casing made ofrefractory material, as fire brick, indicated at a, which maybe molded integrally, and which isvshown exteriorly provided with sheet ,1 metal surface covering indicated at a1.

This casing contains an oven or heat-treatment chamber, A1 which may be referred to as the amechamber, the lower compartment of which, indicated at A2, is separated from Ythe upper part `by means indicated at A3, for supporting in heattreatment position the substance to be heattreated. Said supporting means may be in dif-y ferent forms according to the form and-character of the substance or articleto bexcarriedby it in 1 f the heat-treatment process. In whatever form it 'is' made to suit the article or substance treated this member, A3, is removably supported and positioned in the chamber with clearance for passage between it,-with the article or substance supportedby it,-and the chamber Wall, of the rsupported at the middle part of its length by a stoolor post, A11, which projects up from the bottom of the chamber. The casing is formed with an inlead member, A5, affording access to the heat-treatment chamber by way of the inlead passage, a5.

An upwardly swinging door, A4, at the entrance tothe inlead passage, a5 affords access to the oven chamber for introducing and removing the supporting member, A3, and/or the heat-treated article or substance. An aperture, a4, at the upper side of the casing constitutes a vent passage for the heating current after it has done its Work of heat-treatment in the heat-treatment chamber; and the Waste heat remaining after the heating current has parted with the lgreater portion of its heat communicated to the heat-treated substance is utilized for heating a combustiblevapor-producing means comprising as the main element a retort indicated at B, mounted in a chamber member, C, whichis shown erected on topof the oven casing, A. This retort member, B, may be made of metal and desirably thin for being quickly heated through, by the waste heat current from the heat-treatment chamber. Said retort member has a cover, B1, bolted fluid-tight to the retort body, B, to make the retort chamber completely sealed except as to the oil inlet and gasoutlet hereinafter described.

The retort chamber is partitioned at its upper part and nearly to the bottom by a partitioning web, b1, kwhich is shown formed integral with the cover, B1, extending down into the retort chamber making a tight joint at its Vertical edges with the inner surface of the chamber wall and terminatingr at its lower edge a short distance from the bottom of the retort chamber, leaving a passage, b2, constituting the solev communication between the compartments, b3 and b4, of the retort chamber, Vand thereby between the oil inlet, l0, and gas outlet, Il, arranged as hereinafter described, at the upper ends of the chamber compartments, b3

'and b4, respectively.

f As shown in Figure 1, the retort, B, issupported from an `airpipe line, D, provided for a further f purpose hereinafter explained, leading from a Contact of the liquid being effected by the heat` communicated to the retort by the waste products oi combustion emerging from the 'heat-treat- Y ment chamber, as above described.

The retort B, depending from the air pipe line, D, is connected to said air pipe line at the under side thereof at a four-way iitting, D4, by means of a pipe nipple, l2, connected at the gas outlet of the retort chamber. Said four-way fitting, D4, at the side opposite that at which it is connected to the air pipe line, is'connected, as by the right-and-left threaded coupling, 20, to a three-way tting, 2|, having leading fromveach off the two opposite limbs of said three-way fitting, branch pipe lines, 22, havingV each two branches, 22a, 22h, leading to burners, F, F,` F, F, located below the heat-treated-substance-supporting members, A3, of the heat-treatment chamber for ignition to produce a heating current which is directed against the under side of said Vsupporting member and the material to be heat-treated thereon, and passes up at bothv sides of the heating member and is discharged through the vent aperture, a4, in the topof the casing, A.

The air pipe line, D, at its connection with the tting, D4, terminates in an injector nozzle, d, which protrudes `in the cavity of Athe fitting, D4, ventirely across the same into the opposite limb of said tting and slightly into the entrance of the coupling, 20,' which coupling is interiorly reamed, as'seen at'Za, v(see 'Fig.,5) totaper said entrance somewhat in'contormity to the exterior taper of the nozzle terminal," d, of theV air pipe line, so that the discharge yof air from the nozzle directed into the passage of the coupling, 20, entrains the gas in the fitting and in the nipple, ZI, which connects said tting with the retort chamber, and sucks the' gas' from ythe retort chamber, reducing the pressure in that chamber belowv atmospheric and maintaining constant withdrawal of the gas from'the retort chamber as fast as it is generated from the oil heated to the point of gasification in the manner described. YVFor initially heating the retort to gasify the oil to produce a combustible gas which may be ignited at its discharge from the Vburners',7F, as described, in the construction shown inV FigureV l, the four-way tting, D4, is connected at its fourth limb opposite' the nipple connection with the retort by a'pipe line, 25, with a source of gas, as the public service gas system. A shut oi valve, '26, is provided rat any convenient point in the length of the pipe line preceding its connection with the fitting, D4, and upon opening the Valve, 26, controlling said public service gas line, and the valve, D1, controlling the air pipe line, aerated gas is delivered to andma'y be ignited at all the burners, F. When by this means the retort is heated to the proper'temperature for gasifying oil, the operator will open the oil control valve, e4, to admit oil at a properly Vrestricted rate tol the retort; and after the few seconds necessary for the gasy generated from the oil to be entrained by the injected air along with the gas from the public service gas line, the gas control valve, 26, will be closed and the burners will continue to be supplied by the aerated gas produced fromthe fuel oil in the manner described.V g Y Referring to the form shownY in Figure 2:

When public service gas is not available, or it is preferred not to use it for starting the furnace, there is substituted forthe four-way f1t- Ating, D4, a three-way fitting, d4, and preliminaryy heating is eflectedliy an oil burner'shown at FX, hereinafter called the starter burner, which may be of any familiar form for burning fuel oil, connected to the oil pipe line, E, by a branch line, 3i), in which the flow of oil is controlled by a valve, 3| said starterburner, FX, being mounted `for discharge into the heat-treatment chamber through an air mixing passage, 4D, formed in the rear wall of the heat-treatment chamber. A shutter for this air passage shown at 4|, opened when the starterburner is to be putin service, will be closed when the retort is suic'iently heated to supply the burners, F, with the gas produced from the fuel oil by gasification and aerationas described, so that the starterburner may be shut off.

In actual practice of this invention when using commercial forms and qualities of fuel oil for producing theV highly combustible gas or vapor desirable forY Ythe purpose indicated, and with the retort of the form and construction shown, a'temp'erature of 1000 F., which is readily produced lin the retortjis foundrto vaporize or gasify the oil promptly upon its emergence from vthe oil conduit into the retort during its "descent through. the vertical passage of the retort by the neat radiated from the retort wail; and u' has been demonstrated that the temperature whichris readily produced in the retort on the corriineicial-"form and quality of oilY commonly used for Y-l'ieating industrial appliances, doesl notV Y tion, and that the same isi'not'limited to the particular forms herein shown and described,Y

except in so far as indicated by the appended claims.

" Iclaim: t Y

1. An lapparatus comprising incombination a heat-'treatmentV chamber and a retort for devel# oping gaseous fluid for heatingY the heat-treatment chamber, theretort consisting of acharnber having inlet and outlet connections respectively for'r passing into it liquid Vfuel and for delivering from it combustible'gaseous fluid developed from the liquid fuel in its passage i Y through the retort chamber, said chamber being otherwise sealed against entrance of the liquid fuel and discharge of the resulting gaseous fluid; a supply conduit leading from a source of liquidV fuel to the retort chamber inlet; a discharge conduit connected to the retort chamber outlet;

gas burner means positioned for heating the retort'chamber and the heat-treatment chamber, theV discharge conduit being connected to said gasburner means, and a conduit leading from ya source of air under pressure connected with V'spectively for passing into it liquid fuel, and

for delivering from it gaseous fluid developed from the liquid fuel in its passage through the retort chamber, said chamber being otherwise sealed against entrance of the liquid fuel and discharge of the resulting gaseous fluid; a conduit leading from'a source of liquid fuel to the retort chamber inlet; a discharge conduit leading from the retort chamber outlet; gas burnerl means positioned for heating the retort and the heat-treatment chamber, said discharge conduit supplying fuel to said gas burner means, the

kheat-treatment chamber being interposed between the burner means and the retort at a position for carrying the substance to the heat- `treated and for passage of gaseous products of combustion from the burner means through said Athe' burner after said products have parted with to the heat-treated l prising in combination a retort for developing gaseous uid; a heat-treatment structure having a heat-treatment chamber; means for supplying liquid fuel to the retort; a conduit leading from the retort for discharge of the gaseous iiuid developed in the retort; a conduit leading from a source of air under pressure, connected for discharge into the retort discharge conduit for aerating the gaseous iluid from the retort; burner means operatively associated with the heattreatment chamber for discharging hot products of combustion from said burner means into heating relation to the heat-treated contents of said chamber, and a pipe connected with said retort discharge conduit to supply said burner With gaseous iiuid, the heat-treatment structure having at its upper part an opening for outlet of the hot gaseous products of combustion passing through the Aheat-treatment chamber, the retort n being located in the path of emergence of said hot gaseous products from said outlet; whereby the retort is heated for developing gaseous uid by the waste heat of said products of combustion after heating the heat-treatment chamber.

4. In the combination dened in claim 3, an auxiliary burner positioned for discharging its products of combustion into the heat-treatment chamber, means for supplying liquid fuel directly to said burner, and a branch from the air conduit leading to the burner for aerating such liquid fuel at said burner to provide a combustible mixture for initially heating the retort by way of the heat-treatment chamber.

JOHN W. NELSON. 

